Inlet systems for supersonic aircraft are known in various versions, as for instance from the U.S. Pat. Nos. 3,717,163 and 4,418,879, whose contents are incorporated by reference. In all of these known designs that are dealing with turbojet and ramjet inlets, air for engine operation is supplied over a ramp plate or through a ramp box. These embodiments are, however, unsuitable for an intake system with a turbojet inlet and a ramjet inlet arranged parallel or alongside one another. In the known design, neither control of a differentiated air supply to the respective inlet with a simultaneous control of the entire air supply to the common air intake region, nor a boundary layer bleed off, is possible.
In addition, the intake systems proposed by the known designs cannot be used in the hypersonic range of 4.5 mach to 6.8 mach because of the high occurring pressure stresses and temperature. The highest intake ramp stresses occur in the region of the throat cross-section and the pressure downstream of the throat cross-section rises from approximately 4 bar up to 5.5 bar. This means that the intake system must meet very high structural requirements.